Competition Authorities from France, Italy and Sweden have accepted some concessions made by Booking.com, regarding parity clauses on the contracts executed with hotels that intended to appear in that site. “The three competition authorities had concerns that these so-called parity clauses could restrict competition between Booking.com and other online travel agents, while at the same time they also might prevent other hotel reservation companies from entering the market.” http://www.pcworld.com/article/2912716/bookingcom-will-no-longer-require-european-hotels-to-offer-it-better-room-prices.html
“The deal includes several new concessions from Booking.com over its initial settlement proposal late last year, including the freedom for hotels to allot fewer rooms to Booking.com than to other platforms, and to offer cheaper rooms directly to consumers via offline channels, such as by phone. The agreement, which goes into effect on July 1, is backed by possible noncompliance fines of up to 5% of the company’s global revenue.” (http://www.wsj.com/articles/booking-com-settles-antitrust-complaints-1429623279)
The complete document can be found in here: http://www.konkurrensverket.se/globalassets/english/news/13_596_bookingdotcom-commitment.pdf
Although this measure was accepted by those three countries, others like Germany have refused those concession and now have been left behind with the problem (http://globalcompetitionreview.com/news/article/38456/unprecedented-collaboration-leaves-germany-isolated-price-parity-clauses).